Detection of plasmid-mediated AmpC β-lactamase in Escherichia coli and Klebsiella pneumoniae.
Indian J Med Microbiol
;
2013 Jan-Mar; 31(1): 53-59
Article
in English
| IMSEAR
| ID: sea-147546
ABSTRACT
Background:
Detecting plasmid-mediated AmpC (pAmpC) β-lactamase-producing organism is important for optimal infection control and providing accurate and effective treatment option for physicians.Objectives:
The aim of this study was to investigate the prevalence of pAmpC β-lactamase and compare the results of boronic acid (BA) disk test with other phenotypic tests detecting AmpC positive isolates. Materials andMethods:
A total of 273 clinical isolates of Klebsiella pneumoniae (n 82) and Escherichia coli (n 191) were analysed. The presence of pAmpC β-lactamase was determined by BA disk test, cefoxitin (FOX) screening test, modified three dimensional test (M3DT), and multiplex polymerase chain reaction (PCR). Pulsed-field gel electrophoresis was performed to evaluate the genetic similarities between isolates. To detect extended spectrum β-lactamases (ESBL) in the presence of AmpC β-lactamase, ESBL confirmation test was carried out with and without BA solution.Results:
Of the 273 strains tested, 127 strains were found FOX resistant, 114 were positive by M3DT, 108 were positive in BA disk test, and the multiplex PCR detected 24 pAmpC β-lactamase-positive isolate. The prevalence of AmpC-producing strains was 10.9% in E. coli and 3.6% in K. pneumoniae in the tested population by PCR. CIT and MOX group genes were predominant type in these strains.Conclusion:
These results emphasize that clinical laboratories should consider testing the presence of pAmpC enzymes particularly in FOX-resistant isolates, and BA disk test will improve detection of this emerging resistance phenotype.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Type of study:
Diagnostic study
Language:
English
Journal:
Indian J Med Microbiol
Journal subject:
Microbiology
Year:
2013
Type:
Article
Similar
MEDLINE
...
LILACS
LIS